1. Technical Field
A product is disclosed that is intended to be dispensed in an inverted position, or where the spray valve is directed downward, and which includes powdered or particulate material in the product to be dispensed. The product includes a valve and mesh filter system which avoids clogging of the valve during inverted dispensing. This disclosure is directed to both aerosol and non-aerosol spray systems that are intended to be sprayed downward or in an inverted position.
2. Description of the Related Art
Conventional valves are known for dispensing product in the form of a spray. These products are normally a liquid, an emulsion, a powder or combinations thereof as well as a propellant to expel the product from the aerosol container. Propellants used include pressurized gases such as propane, isobutane, n-butane, and mixtures thereof or pressurized gases such as carbon dioxide, nitrogen, etc. The valves that are used to dispense these products generally have a plastic dip tube with an open end that extends to or near the bottom of the aerosol can.
When the valve is actuated, the product and propellant travel up the dip tube and are dispensed through a nozzle. In some designs, a vapor tap on the valve is used to allow propellant vapor to mix with the product before the mixture is dispensed through the nozzle. Although these designs are fairly successful, they cannot be employed when compressed gases such as carbon dioxide are used as the propellant because compressed gases usually have limited solubility in the product and, when a vapor tap is provided, and the container is in the upright position, there is a rapid “bleed off” of the propellant vapor causing sudden drop in pressure, and eventually total loss of propellant before all of the product has been dispensed. As a result, a substantial amount of product remains in the container and cannot be dispensed and is therefore wasted. Even when liquefied gases such as isobutane and propane are used that are soluble in the product, bleed off occurs to at least some extent, resulting in wasted product remaining in the container.
A valve is typically located internally within the aerosol container. The valve is biased into a closed position. The valve stem cooperates with the valve to open the valve. An actuator engages and pushes the valve stem to open the valve to release the pressurized product. The product is normally dispensed through a spray nozzle. The dispensing rate can vary greatly and depends in large part upon the designs of the nozzle, valve and actuator as well as the propellant, pressure and the product to be dispensed.
Various types of actuators have been utilized. The first and the most basic type is an actuator button that is affixed to the valve stem and which includes the spray nozzle. Depression of the button pushes the valve stem downward to open the valve for dispensing the product. A protective cap is often provided that engages a rim of the container for preventing accidental depression of the button and discharge of the product.
Another type of actuator is an aerosol over cap. An aerosol over cap replaces the conventional protective cap and includes an actuator for opening the valve of the dispenser. Aerosols over caps typically include a base mounted on a rim of the container. Over caps also include an actuator pivotally mounted to the over cap base and that engages the valve stem. The movement of the actuator of the over cap causes a depression of the valve stem to open the valve for dispensing the product through the nozzle.
Another type of actuator is a trigger device. With a trigger actuator, a base is mounted either to the container rim or the mounting cup rim for supporting the trigger. The trigger engages the valve stem. Movement of the trigger from an extended position to a protracted position depresses the valve stem to open the valve and dispense the product. Another design includes a tiltable valve, which includes a spring to bias the stem outwardly to a closed position. Movement of the stem inwardly to tilt the spout opens the valve and releases the product.
For low viscosity products, the spray nozzle and valve are traditionally located on the top of the container for dispensing the product through the spray nozzle with the container in an upright position. For high viscosity products, the product can be dispensed in upright or horizontal positions. However, other high viscosity products may need to be dispensed in an inverted position.
Dispensing containers or cans for high viscosity products are normally designed for dispensing in an upright position. For example, rotary valves may be mounted on the container to control the discharge of the contents from the container when the container is in an inverted position. The valve has a stem that opens the valve upon rotation. Some aerosol dispensers are intended to be stored in an inverted position where an over cap, spray nozzle and the valve are located on the bottom of the aerosol container. Although these types of dispensers are stored in an inverted position, the aerosol container is turned upright to dispense the product from the container.
One inverted aerosol dispensing device includes an under cap secured to a bottom of the container for supporting the container in an inverted position. The actuator moves relative to the under cap for moving the valve stem for discharging the product in a generally downwardly direction through the under cap. Although this valve design is used extensively, it suffers from many disadvantages. One disadvantage is that, when the container is actuated in the inverted position, the open end of the dip tube is above the product level in the container and only propellant is dispensed.
Another dispensing option is the use of a piston pump, commonly called a trigger-sprayer or a fine mist sprayer that are found attached to containers that are typically non-pressurized. The use of such a pump also incorporates a valve enabled by a orifice and a ball that when pressure is applied from within the pump, seals to enable dispensing of product and when pressure is relieved, the ball no longer seals the flow path and product is siphoned into a chamber for subsequent dispensing.
Another disadvantage of conventional aerosol systems is the potential for clogging of the valve orifices by particles that are components of the product. One attempt to solve the clogging problem includes a mesh filter that is attached to the bottom of the dip tube and the product is filtered before it is dispensed. However, clogging can still occur and, if the product includes particulate matter that needs to be dispensed, simple mesh filters are inadequate. In addition to clogging problems, valves with small orifices are difficult to manufacture and small changes in tolerances can cause wide variations in the dispensing of the product. Further, as discussed above, dip tubes, and therefore dip tube filters cannot be used for products that need to be dispensed in an inverted position because large amounts of product will remain below the dip tube opening when the can is inverted.
Therefore, there is a need for an improved aerosol container/product that reliably discharges product in an inverted position and that includes particulate or powdered matter as a part of the product. Similarly, there is a need for an improved non-aerosol spray product that can reliably discharge product in an inverted position that includes particulate or powdered material.